Cinchonism or quinism is a pathological

Pathology

Pathology is the precise study and diagnosis of disease. The word pathology is from Ancient Greek , pathos, "feeling, suffering"; and , -logia, "the study of". Pathologization, to pathologize, refers to the process of defining a condition or behavior as pathological, e.g. pathological gambling....

 condition in humans caused by an overdose of quinine

Quinine

Quinine is a natural white crystalline alkaloid having antipyretic , antimalarial, analgesic , anti-inflammatory properties and a bitter taste. It is a stereoisomer of quinidine which, unlike quinine, is an anti-arrhythmic...

 or its natural source, cinchona

Cinchona

Cinchona or Quina is a genus of about 38 species in the family Rubiaceae, native to tropical South America. They are large shrubs or small trees growing 5–15 metres in height with evergreen foliage. The leaves are opposite, rounded to lanceolate and 10–40 cm long. The flowers are white, pink...

 bark. Quinine is medically used to treat malaria

Malaria

Malaria is a mosquito-borne infectious disease of humans and other animals caused by eukaryotic protists of the genus Plasmodium. The disease results from the multiplication of Plasmodium parasites within red blood cells, causing symptoms that typically include fever and headache, in severe cases...

. In much smaller amounts, quinine is an ingredient of tonic

Tonic water

Tonic water is a carbonated soft drink in which quinine is dissolved. Originally used as a prophylactic against malaria, tonic water usually now has a significantly lower quinine content and is consumed for its distinctively bitter taste...

 drinks, acting as a bittering agent. Cinchonism can occur from therapeutic doses of quinine, either from one or several large doses, or from small doses over a longer period of time, not from the amounts used in tonic drinks, but possibly from ingestion of tonic water as a beverage over a lengthy period of time. Quinidine

Quinidine

Quinidine is a pharmaceutical agent that acts as a class I antiarrhythmic agent in the heart. It is a stereoisomer of quinine, originally derived from the bark of the cinchona tree.-Mechanism:...

 (Class 1A anti-arrhythmic

Antiarrhythmic agent

Antiarrhythmic agents are a group of pharmaceuticals that are used to suppress abnormal rhythms of the heart , such as atrial fibrillation, atrial flutter, ventricular tachycardia, and ventricular fibrillation....

) can also cause cinchonism symptoms to develop with as little as a single dose.

Signs and symptoms

Symptom

Symptom

A symptom is a departure from normal function or feeling which is noticed by a patient, indicating the presence of disease or abnormality...

s of mild cinchonism (which may occur from standard therapeutic doses of quinine) include flushed and sweaty skin, ringing of the ears (tinnitus

Tinnitus

Tinnitus |ringing]]") is the perception of sound within the human ear in the absence of corresponding external sound.Tinnitus is not a disease, but a symptom that can result from a wide range of underlying causes: abnormally loud sounds in the ear canal for even the briefest period , ear...

), blurred vision, impaired hearing, confusion, reversible high-frequency hearing loss, headache, abdominal pain, rashes, drug-induced lichenoid reaction

Drug-induced lichenoid reaction

Drug-induced lichenoid reactions are skin eruptions that occur after ingestion, contact, or inhalation of certain chemicals, with the most common inducers being gold salts, beta blockers, antimalarials, thiazide diuretics, furosemide, spironolactone, and penicillamine...

 (lichenoid

Lichen planus

Lichen planus is a chronic mucocutaneous disease that affects the skin, tongue, and oral mucosa. The disease presents itself in the form of papules, lesions, or rashes. Lichen planus does not involve lichens, the fungus/algae symbionts that often grow on tree trunks; the name refers to the dry and...

 photosensitivity

Photosensitivity

Photosensitivity is the amount to which an object reacts upon receiving photons, especially visible light.- Human medicine :Sensitivity of the skin to a light source can take various forms. People with particular skin types are more sensitive to sunburn...

), vertigo

Balance disorder

A balance disorder is a disturbance that causes an individual to feel unsteady, for example when standing or walking. It may be accompanied by feelings of giddiness or wooziness, or having a sensation of movement, spinning, or floating...

, dizziness

Dizziness

Dizziness refers to an impairment in spatial perception and stability. The term is somewhat imprecise. It can be used to mean vertigo, presyncope, disequilibrium, or a non-specific feeling such as giddiness or foolishness....

, dysphoria

Dysphoria

Dysphoria is medically recognized as a mental and emotional condition in which a person experiences intense feelings of depression, discontent and indifference to the world around them.Mood disorders can induce dysphoria, often with a heightened risk of suicide, especially in...

, nausea

Nausea

Nausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...

, vomiting

Vomiting

Vomiting is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose...

 and diarrhea

Diarrhea

Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...

.

Large doses of quinine may lead to severe symptoms of cinchonism: skin rashes, deafness (reversible), somnolence

Somnolence

Somnolence is a state of near-sleep, a strong desire for sleep, or sleeping for unusually long periods . It has two distinct meanings, referring both to the usual state preceding falling asleep, and the chronic condition referring to being in that state independent of a circadian rhythm...

, diminished visual acuity or blindness, anaphylactic shock, and disturbances in cardiac rhythm or conduction, death from cardiotoxicity. Quinine may also trigger a rare form of hypersensitivity reaction in malaria patients termed blackwater fever

Blackwater fever

Blackwater fever is a complication of malaria in which red blood cells burst in the bloodstream , releasing hemoglobin directly into the blood vessels and into the urine, frequently leading to kidney failure...

 that results in massive hemolysis

Hemolysis

Hemolysis —from the Greek meaning "blood" and meaning a "loosing", "setting free" or "releasing"—is the rupturing of erythrocytes and the release of their contents into surrounding fluid...

, hemoglobinemia

Hemoglobinemia

Hemoglobinemia is a medical condition in which there is an excess of hemoglobin in the blood plasma. This is an effect of intravascular hemolysis, in which hemoglobin separates from red blood cells, a form of anemia. Hemoglobinemia can be caused by intrinisic or extrinsic factors...

, hemoglobinuria

Hemoglobinuria

In medicine, hemoglobinuria or haemoglobinuria is a condition in which the oxygen transport protein hemoglobin is found in abnormally high concentrations in the urine. The condition is often associated with hemolytic anemia, in which red blood cells are destroyed, thereby increasing levels of free...

, and renal failure

Renal failure

Renal failure or kidney failure describes a medical condition in which the kidneys fail to adequately filter toxins and waste products from the blood...

.

Patients treated with quinine may also suffer from hypoglycemia

Hypoglycemia

Hypoglycemia or hypoglycæmia is the medical term for a state produced by a lower than normal level of blood glucose. The term literally means "under-sweet blood"...

 (especially if administered intravenously) and hypotension

Hypotension

In physiology and medicine, hypotension is abnormally low blood pressure, especially in the arteries of the systemic circulation. It is best understood as a physiologic state, rather than a disease. It is often associated with shock, though not necessarily indicative of it. Hypotension is the...

 (low blood pressure

Blood pressure

Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...

).

Most symptoms of cinchonism (except in severe cases) are reversible and disappear once quinine is withdrawn.

Quinine, like chloroquine, inactivates enzymes in the lysosomes of cells, and has an anti-inflammatory effect, hence its use in rheumatoid arthritis. However switching off these enzymes can also cause abnormal accumulation of glycogen and phospholipids in lysosomes, causing a toxic myopathy

Myopathy

In medicine, a myopathy is a muscular disease in which the muscle fibers do not function for any one of many reasons, resulting in muscular weakness. "Myopathy" simply means muscle disease...

. It is possible this is the root cause of cinchonism.

External links

• IPCS INTOX databank entry for quinine
• Side effect of quinine for nocturnal cramps—letter printed in the BMJ
  BMJ
  BMJ is a partially open-access peer-reviewed medical journal. Originally called the British Medical Journal, the title was officially shortened to BMJ in 1988. The journal is published by the BMJ Group, a wholly owned subsidiary of the British Medical Association...
  
  with a photograph of hands affected by lichenoid photosensitivity
• Effects of Quinine on the Excitability and Voltage-Dependent Currents of Isolated Spiral Ganglion Neurons in Culture